Literature suggests that in sheep, indirect selection for testis size may lead to correlated changes in ovulation rate, an important factor in female prolificacy. We examined the chromosomal location of QTL for 4 testis weight (TW) traits, and live weight (LW) in a flock of 9 ITT x Merino backcross families (male nmax=269). To our knowledge, this is the first QTL study of any testicular traits in sheep. It reveals 13 QTL (pless than or equal to 0.05, chromosome-wide); 5 for LW, 4 for TW traits apparently driven by LW, and 4 TW QTL on OAR20 and OAR24 independent of LW. OAR20 is largely syntenic with BTA23, previously reported in association with ovulation and twinning rates in cattle. Pursuing the underlying causes of these associations may shed light on male (and potentially female) fecundity in sheep and cattle.